What do the following two equations represent? $-5x+5y = 5$ $5x-5y = 4$
Solution: Putting the first equation in $y = mx + b$ form gives: $-5x+5y = 5$ $5y = 5x+5$ $y = 1x + 1$ Putting the second equation in $y = mx + b$ form gives: $5x-5y = 4$ $-5y = -5x+4$ $y = 1x - \dfrac{4}{5}$ The slopes are equal, and the y-intercepts are different, so the lines are parallel.